Partial interpenetration

Fd h = 0) should increase as when the chain concentration increases. A very different picture is predicted in the case of adsorbing polymers [49]. The layer of adsorbed chains may be partially interpenetrated by free chains in the bulk and therefore the range and strength of the attraction are not determined by the solution concentration. Instead, they are rather sensitive to the coverage and thickness of the adsorbed chains which depend essentially on the solvent quality and on the mean chain length in the dilute regime. 

An intermediate case would be a complex in which two large molecules associate with only partial interpenetration of part of one molecule into a cavity of the... 

The description of the spatial localization of bound substrate(s) with respect to the receptor also requires some formalism. Whereas external addition complexes may be written as [A, B] or [A//B], the mathematical symbols of inclusion c [1.27] and of intersection n [1.37], respectively, have been introduced for the inclusion of a into p, [ct c p], and for the partial interpenetration of a and p, [a n p]. 

The existence of compounds containing more than one interpenetration symmetry element cannot be ruled out. This requires the introduction of an additional sub-classification, similar to the division of class I, i.e. class I la with a unique full interpenetration symmetry element and class lib with different partial interpenetration symmetry elements (only one real example is known [15]). 

Figure 13.15. (a) Schematic set-up of the surface plasinon resonance experiment (b) experimental results (symbols) with calculated curves (solid lines). Spectra of 0, 2,4, 6, and 8 monolayers of a LB-filin of 3-thienylpcntadecanoic acid on an Ag film (450 nm) ate shown in curves a-e, respectively. Evaluation of the results indicate a thickness of 2.33 nm per monolayer which is smaller than the geometric film thickness calculated from the length of the molecule at a tilt of 10° (c) schematic representation of a bi-layer on a hydrophilic substrate. In the layers the molecules are oriented upright and the thiophene parts (T) partially interpenetrate, resulting in a diminished layer thickness. Reproduced fi om ref 97 by kind permission of Elsevier. 

The structure of the diffuse weld interface resembles a box of width X, with fractal edges containing a gradient of interdiffused chains as shown by Wool and Long. When the local stress at a crack tip exceeds the yield stress, the deformation zone forms and the oriented craze fibrils consist of mixtures of fully entangled matrix chains and partially interpenetrated minor chains. 

Fig. 8.9. A real cycle relevant to Eq. (8.56). This cycle differs from the ideal one (Fig. 8.3) in two respects. (1) The two solute particles a and b are brought to a new configuration which, in general, involves partial interpenetration. (2) The pair a and b is replaced by a single molecule denoted a-b. Therefore, two new steps are added, involving the work and...

Some properties of IPNs are simple averages of the properties of the eom-ponent polymers. Sometimes the values are higher than expeeted. Density measurements on PU/PS simultaneous IPNs showed a density higher than expected. This was due to the partial interpenetration of chains of the rubbery and glassy polymer components." ... 

Total degree of interpenetration full interpenetration vector, one vector is enough to describe the entire interpenetration partial interpenetration vectors, several vectors needed to describe the interpenetration total interpenetration vector. 

Type lb needs more than one vector to connect all nets, and these are called partial interpenetration vectors (PIV). These are included in the Z-symbol as where Zn is the number of integer translations such as the [1,0,0], [0,1,0] and [0,0,1] vectors, and Z the number of centering translations, that is where x,y and z in the vector fx,y,z] has a values of 0.5 or 0. In this case, the degree of interpenetration will be ... 

Finally, the structure of (Me2NH2)i 75[InL]j 75 (DMF)i2(H20)io, H4L = biphenyl-3,3, 5,5 -tetra(phenyl-4-carboxylic acid) shows the peculiar property of partial interpenetration. The structure is nominally composed of two interpenetrating diamond networks however, whereas one net is fully occupied, the second net is not only equally disordered over two positions (which is unusual in itselO, but the total occupancy of these two positions is only ca. 75%. 

The thicknesses of BOx on the carbon electrode and of PEI on BOx increase from a one- to a two-layered sample. However, a three-layered sample does not show further increase in either BOx or PEI thickness, as neighboring BOx and PEI layers partially interpenetrate. The reason for this is the BOx and PEI layers are intermixed, and the architectures for one-layer and two-layer samples are ordered (with some degree of intermixing) and stable due to the strong electrostatic attraction between the... 

Several partially interpenetrating polymeric networks (IPN) were made from chemically different linear elastomers... 

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